Are you sure it is white and not just really light/clean splash.
But really it could easily be a white if say the parents are both carrying one copy of recessive White, if so then out of the particular pairing of the ones carrying the one white gene, about a quarter of their chicks should be solid Recessive White.
And recessive white is masking another color under it so it is likely masking Blue Black or Splash under it but there wont be a way to know unless you breed and see.
But say for instance you breed a White that was masking black to a blue, This would produce half blues and half black F1s. So now say you bred those Blue F1s together, you would still get genetically 50% Blues, 25% Blacks, and 25 % splash ( though a large hatch would be needed for that to be real accurate) But they would be genetically those colors, but 25% of the total, regardless of what BBS phase they are underneath, would be Solid Recessive Whites. And Recessive White can mask any color, not just BBS. And since all White Silkies are masking a color underneath the white, yours would be no different so you would still call it a White Silkie, but knowing that it is most likely masking B B or S since your hatched Blue and Splash chicks with it, that would give you a better chance of knowing what you would get if you were to breed it than you would have if you were just breeding with any random white silkie becuase as I said they can be masking any color and you never know what unless you know their genetic history or breed them to see through trial and error.
